The compound (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one or one of its pharmaceutically acceptable salt forms (known as xe2x80x9cFlavopiridolxe2x80x9d) is an immunomodulator and antiinflammatory agent (U.S. Pat. No. 4,900,727), and inhibitor of oncogene-encoded kinases or growth factor receptor tyrosine kinases (U.S. Pat. No. 5,284,856). Flavopiridol is a strong inhibitor of cyclin dependent kinases (CDKs) including CDK1, CDK2, CDK4, CDK6 and CDK7, (cdk1/clyclin B; cdk2/cyclin A; cdk2/cyclin E; cdk4/cyclinD; cdk6/cyclinD; cdk7/cyclin H) with the potential to cause inhibition of cell cycle progression in G1 and G2 by multiple mechanisms relatable to cdk inhibition. See International Journal of Oncology 9:1143-1168 (1996). Also, Flavopiridol has been shown to inhibit the EGF receptor family, the receptor associated SRC family kinases, and signal transducing kinases. In vitro and in vivo experiments have shown that Flavopiridol is able to inhibit a broad type range of human tumors, leukemias and lymphomas.
(xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one or a pharmaceutically acceptable salt thereof crystallizes into numerous solvates with solvents such as ethanol, DMSO, methanol, acetonitrile/isopropanol, ethanol/isopropanol, and isopropanol and solvate hydrates such as ethanol/ and isopropanol/water combinations. The superior solvate form is the Flavopiridol hydrochloride ethanol solvate form (hereafter xe2x80x9cForm IIxe2x80x9d).
The use of ethanol over the other solvents used to produce solvates presents advantages of less toxicity (e.g., methanol, isopropanol solvates).
A subject of the instant invention is Form II of (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperindinyl]-4H-1-benzopyran-4-one, this means the solvate of ethanol with (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4one hydrochloride. Said Form II can be described by x-ray powder diffraction in the following, obtained using Cu K-alpha radiation:
and more preferably as:
Also, Form II is further identified as:
Further, Form II may be identified as:
Form II may also be identified as in Table 1:
Form II can be used as a pharmaceutical, optionally together with pharmaceutically acceptable carriers and/or excipients. Furthermore, it can be used for the production of other polymorphs or pseudopolymorphs of (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one.
Form II is hygroscopic. It can be used in water free form or in a form with a certain water content. The use in a form, which is essentially free from water is preferred.
Another subject of the instant invention is a process for the production of Form II of (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one.Steps of the production process of Form II of (xe2x88x92)-cis-2-(2-chlorphenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1methyl)piperidinyl]4H-1-benzopyran-4-one are
a) dissolving a sufficient amount of (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4one hydrochloride in a sufficient amount of ethanol thus forming a mixture,
b) heating the mixture to about 50 to about 80xc2x0 C.;
c) optionally filtering off undissolved material from the mixture thus forming a solution
d) concentrating the solution until about 50 to about 90% of the volatiles are removed,
e) cooling the solution, for example, to about 0 to 10xc2x0 C. and optionally isolating (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one hydrochloride crystals thus obtained; and
f) optionally drying the crystals.
A xe2x80x9csufficient amountxe2x80x9d of (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4one hydrochloride is that amount sufficient to be dissolved and heated according to the steps of the invention to form enough crystals to be recovered. Likewise, a xe2x80x9csufficient amountxe2x80x9d of ethanol is that amount sufficient to dissolve at least a portion of the (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4one hydrochloride added thereto in order to dissolve a portion thereof. These amounts can be experimentally determined.
The xe2x80x9cvolatilesxe2x80x9d are those agents which may be evaporated during heating such as ethanol and/or water.
The present invention also includes a pharmaceutical composition comprising a therapeutically effective amount of Form II and a pharmaceutically acceptable carrier.
A xe2x80x9cpharmaceutically acceptable carrierxe2x80x9d is an agent which is non-toxic, does not interfere with the therapeutic profile of Form II and is appropriate to the method of administration. Form II is preferably administered by the intravenous route over an appropriate period of time for cancer chemotherapy. Preferably, Form II is mixed with one or more pharmaceutically acceptable carriers. For example, Form II may be mixed with iso-osmotic and pH controlled liquids such as water, dextrose/water or saline/water for injection intravenously into the patient.
A xe2x80x9ctherapeutically effective amountxe2x80x9d of Form II and will vary with the individual, concomitant therapy, the disease, and other variable factors. Typically, this amount will be about 0.001 mg/kg to 100 mg/kg per day.
Form II is useful as a protein kinase inhibitor and cyclin dependent kinase inhibitor, and is useful in the treatment for various forms of cancer.
In step a) of the said production process one part of (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one is dissolved in 10 to 30, preferably 15 to 25 in particular 19 to 21 parts of ethanol. Preferably, ethanol which is essentially free from water is used. (xe2x88x92)-cis-2-(2-Chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one can be obtained as disclosed in U.S. Pat. No. 5,284,856; preferably, (xe2x88x92)-cis-2-(2-chlorophenyl)-5,7-dihydroxy-8[4R-(3S-hydroxy-1-methyl)piperidinyl]-4H-1-benzopyran-4-one is produced as outlined in Example 1 below.
The heating of the obtained mixture is carried out for preferably about one hour to 50 to 80, preferably 60 to 80, and in particular 70 to 79xc2x0 C. If solid substance is observed in the solution, it can be filtered off, preferably while the solution is still hot.
The obtained solution is concentrated by methods known to a person skilled in the art, preferably by distillation under atmospheric or under reduced pressure. Concentration is carried out until 50 to 90%, preferably 55 to 85%, in particular 60 to 80% of the volatiles have been removed.
The remaining suspension is subsequently cooled, preferably to about 0 to 10xc2x0 C. and the obtained crystals are removed from the suspension, preferably by filtration.
The obtained crystals can be dried, preferably under reduced pressure.